Add C++ agentic examples using agt and Mistral

[0x9dhcf]

Cookbook Pull Request

Description

Adds four progressive examples showing how to use Mistral models from C++ using agt, a minimal provider-agnostic C++ library for building LLM-powered agents.

The examples cover:

• Direct completion with thinking effort control
• Agent with tool calling and persistent SQLite session
• Streaming with full lifecycle hooks and parallel tool calls
• MCP server integration

agt is an independent open-source library, not a production framework. It grew out of chatty, a personal terminal assistant. These examples are shared as a starting point for developers working in C++ codebases who want to use Mistral models.

Dependencies:

• C++23 compiler,
• CMake 3.21+,
• libcurl,
• SQLite3,
• Node.js (example 4 only).

All C++ dependencies are fetched automatically via CPM.

Type of Change

• New Cookbook
  • Markdown File

Cookbook Checklist

• My code is easy to read and well structured.
• I've tagged the versions of any dependency required.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• My changes generate no new warnings or errors.

README.md Checklist

• README file updated.

Additional Context

All four examples have been tested and produce the expected output shown in the README. The streaming example confirms that Mistral supports parallel tool calls, the model requested all four tools in a single turn before composing its final answer.